Cardiometabolic syndrome among general adult population in Ghana: The role of lipid accumulation product, waist circumference‐triglyceride index, and triglyceride‐glucose index as surrogate indicators

Abstract Background Visceral obesity and insulin resistance contribute to developing cardiometabolic syndrome (MetS). We investigated the predictive abilities of lipid accumulation product (LAP), waist circumference‐triglyceride index (WTI), and triglyceride‐glucose (TyG) index for MetS screening among the general Ghanaian adults. Methods The final prospective analysis included 4740 healthy adults aged 30–90 years from three communities comprising Ejisu, Konongo, and Ashanti Akim Agogo in Ghana. Self‐structured questionnaire pretested was used to collect sociodemographic, anthropometric, and clinical data. Blood samples were taken after fasting to measure glucose and lipid levels. LAP, WTI, and TyG were calculated from standard equations. MetS was defined by the International Diabetes Federation criteria. Receiver operating characteristic (ROC) curves and multivariable logistic regression were utilized to evaluate the potential of the three indices in identifying MetS. Results Of the 4740 participants, 39.7% had MetS. MetS was more common in females (50.3%) than in males (22.2%). Overall, LAP ≥ 27.52 yielded as the best index for MetS with the highest area under the ROC curve (AUC) (0.866). At cut‐off LAP point of ≥23.87 in males and ≥33.32 in females, an AUC of 0.951 and 0.790 was identified in MetS prediction, respectively. LAP was an independent risk measure of MetS for both males (45.6‐fold) and females (3.7‐fold) whereas TyG was an independent risk measure for females (3.7‐fold) only. Conclusions MetS is increasing among the general adult population. LAP and TyG are important sex‐specific risk measures to screen for MetS among the general adult population in our cohort.


| INTRODUCTION
Metabolic syndrome (MetS) is a group of metabolic disorders, characterized by central obesity, hypertension, dysglycemia, high triglyceride (TG) levels, and low levels of high-density lipoprotein cholesterol (HDL-C). [1][2][3] MetS is a major concern for public health worldwide and has been linked to higher risks of cardiovascular disease (CVD), type 2 diabetes, and mortality. 4,5 MetS occurrence ranges between 10% and 84% globally, and it is influenced by environmental factors, gender, ethnicity, and MetS classification criteria used. 6,7 In sub-Saharan Africa, its prevalence is 18% 8 and ranges from 12% to 31% in Ghana. 9 The exact cause of MetS is not fully understood, but research suggests visceral obesity and insulin resistance (IR) as key factors of the condition. 10 Visceral adiposity and IR are thus decent MetS predictors.
Magnetic resonance imaging and computed tomography are considered the standard methods for evaluating visceral adiposity, 11 but are seldom utilized for routine investigations because of their high cost, radiation risks to patients, and laborious nature. Therefore, it is critical to develop a simple and clinically applicable visceral obesity surrogate indicator. As such, obesity indices are suggested to assess body fat levels and distribution, enabling monitoring of metabolic disorders. Body mass index (BMI), although being the most commonly used obesity index, has limitations in identifying fat distribution in the body. 12 New indices have thus been proposed to assess visceral obesity. Among the recently proposed indices is lipid accumulation product (LAP). The LAP is a reliable indicator of central lipid buildup, and it was superior to BMI for predicting CVD risk. 13 It is a combination of waist circumference (WC) and blood TGs. 13 LAP is a valuable diagnostic tool for identifying IR, nonalcoholic fatty liver, and MetS, as evidenced by multiple studies. [13][14][15] IR, another primary driving factor of MetS is diagnosed by hyperinsulinaemic-euglycaemic clamp (HEC), a more complex and cumbersome method. Triglyceride-glucose (TyG) and waist circumference-triglyceride (WTI) indices are simple yet useful surrogate predictors of IR and have been shown as strong predictors for MetS in the Korean, 16 United States, 17 and the Chinese 18,19 populations.
Despite these novel findings and the usefulness of these measures in other populations, no study to the best of our knowledge, have simultaneously compared the value of these indices (LAP, WTI, and TyG) for screening MetS among healthy Ghanaian adults. It is in light of this that this study aimed to explore the potential of these three easily calculated and cheap indices as predictors of MetS among the general Ghanaian adult population.

| Study design/setting
This was a cross-sectional study carried out across multiple centers from January 2022 to September 2022. We enrolled participants from three communities namely, Ejisu, Konongo, and Asante-Akim Agogo in the Ashanti Region, Ghana. Initially, cities were split into geographic zones, and then these zones were further divided into smaller units called primary sampling units. These units were randomly chosen for further sampling. The participants were evaluated using a standardized procedures that included in-person interviews and clinical exams. These evaluations were conducted at the study centers and followed standard protocols.

| Study population and inclusion/exclusion criteria
A total of 5559 adults were initially recruited into the study. Healthy noninstitutionalized adults aged 30-90 years and residing in the Ejisu, Konongo, and Asante-Akim Agogo communities were included in the study. Participants with known chronic illness and infections and were either attending medical check-up or taking medications were excluded from the study. Other exclusion criteria were participants with missing data for anthropometric measurements (n = 199), blood pressure (n = 44), fasting plasma glucose (n = 23), or lipid levels (n = 121) and those aged below 30 years and above 90 years (n = 432) were excluded from this study. The final analysis included a total of 4740 adults.

| Sample size estimation
With 7.4% MetS prevalence, 20 expected 5% difference, and 0.05 type I error (α), 105 adults was the determined sample size. We extrapolated the population size to 4740 to increase the study's statistical power.

| Ethical approval
Approval was sought from the Committee on Human Research, Publication and Ethics (CHRPE) at the School of Medical Sciences of the Kwame Nkrumah University of Science and Technology (KNUST), Ghana and we obtained written consent from every participant before the study began.

| Data collection
Before recruiting participants, the purpose of the study was exaplained to them, and only those who consented to participate were included. A questionnaire was used to gather data on sociodemographic characteristics, including age and sex.

| Blood pressure measurement
Trained nurses followed the American Heart Association (AHA) guidelines to measure blood pressure with a mercury sphygmomanometer and stethoscope. 21 Two readings were taken, and the mean of the two, rounded to the nearest 2.0 mmHg, was documented.  and GraphPad Prism 8.0.1 (GraphPad LLC) were utilized for analysis.

| Clinical and anthropometric measurements
Categorical data were expressed as frequency (proportion). Continuous data were checked for normality using Kolmogorov-Smirnov test.
Nonparametric data were expressed as median (interquartile range).
Nonparametric data was analyzed with Mann-Whitney U-test to evaluate differences between groups, while χ 2 test was used to examine the relationship between sociodemographic characteristics (e.g., sex) and MetS. Receiver operating characteristic (ROC) curves and multivariable logistic regression were utilized to assess the potential of all three indices in identifying MetS. The cut-off values for the indices generated on the ROC curves analysis were stratified into high and low and logistics regression analysis were performed. All statistical results obtained were deemed significant at p < 0.05. However, HDL-C levels were significantly lower in MetS group than ANTO ET AL. | 3 of 10 non-MetS group. LDL-C did not differ between the two groups. In addition, MetS group had significantly elevated anthropometric indices (LAP, TyG, and WTI) (all p < 0.0001) ( Table 1).

| Prevalence of MetS and its components in males and females
1881/4740 (39.7%) of the participants were diagnosed with MetS.
MetS and its components were more prevalent in females than males.
Additionally, MetS varied significantly between male and female subjects. Of the individual MetS components, only central obesity and reduced HDL-C differed between both sexes (both p < 0.0001) ( Figure 1). for females, it was ≥8.56.  [31][32][33] This difference in prevalence is not surprising because MetS is a sex-specific condition resulting from multiple interconnected risk factors. 33 But we also believe that the much higher prevalence in females than males could be due to the higher females than males in the current study (female: male ratio was 4:1).

| The anthropometric indices for predicting MetS
Our study also reveals LAP as the best measure to discriminate MetS among the subjects as supported by our ROC analysis and logistic regression analysis: LAP showed the highest AUC of 0.951, 0.790, and 0.866 for males, females, and both sexes respectively; it could also independently predict MetS among the subjects in the adjusted logistic regression model. In this study, LAP proved "outstanding" (AUC ≥ 0.9) for MetS prediction in males but proved "excellent" (0.8 ≤ AUC < 0.9) in females per Homer and Lemeshow's criteria 34 for AUC. In keeping with our results, Sun et al. 17 found LAP as the index with the highest diagnostic potential for MetS in United States adults (overall AUC: 0.857). In their study, however, they included visceral adiposity index (VAI) in their comparison. Likewise, Shin et al. 16 found LAP as the best index for MetS prediction among T A B L E 4 Associations between MetS incidence and the indices.